Examples of the leading causes of human death include malignant tumors, heart disease, and cerebrovascular disease. Among them, the mechanism of causing malignant tumors is complicated, so that the malignant tumors, in particular, can be said to be a hard-to-prevent and hard-to-treat disease.
Examples of a symptom that causes malignant tumors include tissue fibrosis. For instance, when liver fibrosis advances, this causes hepatic cirrhosis, leading to liver cancer. In addition, fibrosis occurs in the lung, kidney, heart, skin, etc. Non-Patent Literature 1 describes the outcome of a clinical trial on pirfenidone involved with fibrosis treatment.
The present inventors have reported low-molecular-weight compounds in three publications (Non-Patent Literatures 2 and 3 and Patent Literature 1). Non-Patent Literatures 2 and 3 describe low-molecular-weight compounds that exert an inhibitory effect on proliferation of liver cancer cells and an inhibitory effect on a Wnt/β-catenin signal. However, neither Non-Patent Literature 2 nor 3 describes what kinds of the structure and function of a compound cause the compound to exert a growth inhibitory effect on liver cancer cells.
Patent Literature 1 describes that PN-1-2, PN-3-4, PN-3-13, HC-1, and IC-2 inhibit a Wnt/β-catenin signal in a mesenchymal stem cell, thereby inducing differentiation of the mesenchymal stem cell into hepatocytes. This literature, however, discloses nothing about inhibition of proliferation of cancer cells.